Field
Aspects of the present disclosure relate generally to generating temperature-compensated reference voltages, and more particularly, to a temperature-compensated reference voltage generator that generates temperature-compensated currents by impressing controlled voltages across resistors.
Background
A bandgap reference voltage source generates a reference voltage VREF that is substantially constant over a defined (very wide) temperature range. In discrete circuit or integrated circuit (IC) applications, the reference voltage VREF is used in many applications, such as for voltage regulation where a supply voltage is regulated based on the reference voltage.
The bandgap reference voltage generated is typically around 1.2 Volts because the source of the voltage is based on the 1.22 eV bandgap of silicon at zero (0) degree Kelvin. As the bandgap reference voltage VREF is about 1.2 Volts, a bandgap reference voltage source requires a supply voltage greater than the 1.2 Volts, such as a supply voltage of 1.4 Volts to accommodate, for example, a 200 millivolt (mV) drain-to-source voltage Vds of a field effect transistor (FET) used for biasing the bandgap reference voltage.
Currently, because of continued reduction in the size of FETs used in ICs and the further need to reduce power consumption, many circuits operate with supply voltages below the bandgap voltage of 1.2 Volts. In response to such need, bandgap reference voltage sources have been designed to operate with supply voltage below 1.2 Volts.